Preschool Physics Experiment - Will it Float or Sink?

This is a common preschool science experiment, but it’s a good one on hot summer days or days when you’re trapped in the house due to rain or snow. Finding common household items that float or sink in water is a great way to teach your preschooler about weights. Find out if adding salt to your water changes what objects sink or float.

What your Preschooler will Learn from this Preschool Physics Experiment

Objects that are heavier than water will sink, while objects that are lighter will float.
When you add salt to your water, you make it heavier so objects that sunk before will now float.

What you Need for this Preschool Physics Experiment

Empty plastic jug (An empty gallon milk container would be perfect or a large Tupperware container with a good seal).
Water
Two big bowls
Salt
Objects that won't be damaged if they get wet. Good examples are going to be plastic Lego's, a juice box, a water bottle, plastic toys, and action figures. If you really want to trick your preschooler, find a rock and a piece of bark that’s about the same size.

What To Do

Step one: Have your preschooler pick up your empty plastic jug.

Step two: Fill up the jug with water.

Step three: Have your preschooler try to pick it up. Don’t let them hurt themselves swinging your jug around or trying to pick it up though. From this they’ll learn that water is heavy.

Step four: Fill your two bowls with water.

Step five: In one of your bowls add salt. Stir it to make sure it dissolves completely.

Step six: Have your preschooler drop the objects one by one into the water bowl. If your preschooler is old enough, have them guess which objects will float or sink. Then put the same object into the salt water bowl. Have your preschooler guess whether it will sink or float. Keep notes to make this preschool science experiment even more scientific.

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